This study investigated the effects of modified phosphatidylcholine (PC) with different alkyl chain lengths (PC_C14 and PC_C16) and covalently attached caffeic acid on the physical and oxidative stability of 70% fish oil-in-water emulsions. High fat emulsions were produced using different amounts of modified PCs in combination with sodium caseinate and soy-PC. Results showed that the physical stability of the emulsions was improved with increasing concentrations of modified PCs, due to their high surface activity. Emulsion stabilized with PC_C14 led to smaller droplets and higher viscosity, whereas PC_C16 had higher protein surface load, which may result in a thicker interfacial layer. Modified PCs enhanced the oxidative stability of the emulsions due to the attachment of caffeic acid to the glycerol backbone of PC, which brings the antioxidant in the vicinity of oil-water interface. PC_C16 led to less formation of primary and secondary oxidation products compared to PC_14 at their equivalent concentrations.